The identification of Lgr5 as an intestinal stem cell marker has made it possible to isolate and study primary stem cells from small intestine. Using the cell cycle specific expression og the mKi67 gene, we generated a novel Ki67-RFP knock-in allele which identifies dividing cells. Using Lgr5-GFP;Ki67-RFP mice, we isolated CBCs with distinct Wnt signaling levels and cell cycle features, and analyzed their global gene expression pattern using microarrays. We concluded that the cycling Lgr5hi stem cells exit the cell cycle in transition into the secretory lineage. Lgr5med Ki67low intermediate precursors reside in the zone of differentiation, resemble quiescent stem cells and generate the Dll1+ secretory precursors and the label retaining cells. Our findings support the cycling stem cell hypothesis and highlight the heterogeneity of early progenitors during lineage commitment.
Mapping early fate determination in Lgr5+ crypt stem cells using a novel Ki67-RFP allele.
Specimen part
View SamplesThe significance of cardiac stem cell (CSC) populations for cardiac regeneration remains disputed. Here, we apply the most direct definition of stem cell function (the ability to replace lost tissue through cell division) to interrogate the existence of CSCs. By single-cell mRNA sequencing and genetic lineage tracing using two Ki67 knockin mouse models, we map all proliferating cells and their progeny in homoeostatic and regenerating murine hearts. Cycling cardiomyocytes were only robustly observed in the early postnatal growth phase, while cycling cells in homoeostatic and damaged adult myocardium represented various noncardiomyocyte cell types. Proliferative postdamage fibroblasts expressing follistatin-like protein 1 (FSTL1) closely resemble neonatal cardiac fibroblasts and form the fibrotic scar. Genetic deletion of Fstl1 in cardiac fibroblasts results in postdamage cardiac rupture. We find no evidence for the existence of a quiescent CSC population, for transdifferentiation of other cell types toward cardiomyocytes, or for proliferation of significant numbers of cardiomyocytes in response to cardiac injury. Overall design: We generated transciptome data from proliferative cardiac cells collected from 3, 7 or 14 days following myocardial infarction (MI) or sham surgery. This series includes single-cell transcriptome data from (Ki67-RFP+) cardiac cells collected from neonatal murine hearts, adult homeostatic murine hearts or adult murine hearts collected 14 days following myocardial infarction (MI), ischemic/perfusion (I/R) or sham surgery.
Profiling proliferative cells and their progeny in damaged murine hearts.
Specimen part, Subject, Time
View SamplesHigh VEGFC mRNA expression of AML blasts is related to increased in vitro and in vivo drug resistance. The prognostic significance of VEGFC on long-term outcome and its associated gene expression profiles remain to be defined. We studied the effect of VEGFC on treatment outcome and investigated gene expression profiles associated with VEGFC using microarray data of 525 adult and 100 pediatric AML patients. High VEGFC expression appeared strongly associated with reduced complete remission rate, reduced overall and event-free survival (OS and EFS) in adult AML. Multivariable analysis established high VEGFC as prognostic indicator independent of cytogenetic risk, FLT3-ITD, NPM1, CEBPA, age and WBC. Also in pediatric AML high VEGFC was related to reduced OS. A unique series of differentially expressed genes was identified that distinguished AML with high VEGFC from AML with low VEGFC, i.e., 331 upregulated genes (representative of proliferation, VEGF-receptor activity, signal transduction) and 44 downregulated genes (e.g. related to apoptosis) consistent with a role in enhanced chemoresistance. In conclusion, high VEGFC predicts adverse long-term prognosis and provides prognostic information in addition to well-known prognostic factors.
High VEGFC expression is associated with unique gene expression profiles and predicts adverse prognosis in pediatric and adult acute myeloid leukemia.
Specimen part, Subject
View SamplesNLRC5 is a member of the NLR family of proteins. The observation that NLRC5 is found in the nucleus prompted us to perform a gene array to identify putative target genes of NLRC5. We generated Jurkat T cell lines that stably express either the wild-type or mutant forms of NLRC5 harboring mutations in the nucleotide binding domain (NBD): Walker A (deficient in nucleotide binding), Walker B (deficient in nucleotide hydrolysis), and the combined Walker AB, carrying both mutations.
NLR family member NLRC5 is a transcriptional regulator of MHC class I genes.
Cell line
View SamplesAlmost a quarter of pediatric patients with Acute Lymphoblastic Leukemia (ALL) suffer from relapses. The biological mechanisms underlying therapy response and development of relapses have remained unclear. In an attempt to better understand this phenomenon, we have analyzed 41 matched diagnosis relapse pairs of ALL patients using genomewide expression arrays (82 arrays) on purified leukemic cells. In roughly half of the patients very few differences between diagnosis and relapse samples were found (stable group), suggesting that mostly extra-leukemic factors (e.g., drug distribution, drug metabolism, compliance) contributed to the relapse. Therefore, we focused our further analysis on 20 samples with clear differences in gene expression (skewed group), reasoning that these would allow us to better study the biological mechanisms underlying relapsed ALL. After finding the differences between diagnosis and relapse pairs in this group, we identified four major gene clusters corresponding to several pathways associated with changes in cell cycle, DNA replication, recombination and repair, as well as B cell developmental genes. We also identified cancer genes commonly associated with colon carcinomas and ubiquitination to be upregulated in relapsed ALL. Thus, about half of relapses are due to selection or emergence of a clone with deregulated expression of a genes involved in pathways that regulate B cell signaling, development, cell cycle, cellular division and replication.
Genome-wide expression analysis of paired diagnosis-relapse samples in ALL indicates involvement of pathways related to DNA replication, cell cycle and DNA repair, independent of immune phenotype.
Sex, Specimen part, Disease
View SamplesBackground and Purpose—Analyzing genes involved in development and rupture of intracranial aneurysms can enhance knowledge about the pathogenesis of aneurysms, and identify new treatment strategies. We compared gene expression between ruptured and unruptured aneurysms and control intracranial arteries. Methods—We determined expression levels with RNA sequencing. Applying a multivariate negative binomial model, we identified genes that were differentially expressed between 44 aneurysms and 16 control arteries, and between 22 ruptured and 21 unruptured aneurysms. The differential expression of 8 relevant and highly significant genes was validated using digital polymerase chain reaction. Pathway analysis was used to identify enriched pathways. We also analyzed genes with an extreme pattern of differential expression: only expressed in 1 condition without any expression in the other. Results—We found 229 differentially expressed genes in aneurysms versus controls and 1489 in ruptured versus unruptured aneurysms. The differential expression of all 8 genes selected for digital polymerase chain reaction validation was confirmed. Extracellular matrix pathways were enriched in aneurysms versus controls, whereas pathways involved in immune response and the lysosome pathway were enriched in ruptured versus unruptured aneurysms. Immunoglobulin genes were expressed in aneurysms, but showed no expression in controls. Conclusions—For rupture of intracranial aneurysms, we identified the lysosome pathway as a new pathway and found further evidence for the role of the immune response. Our results also point toward a role for immunoglobulins in the pathogenesis of aneurysms. Immune-modifying drugs are, therefore, interesting candidate treatment strategies in the prevention of aneurysm development and rupture. Overall design: RNA sequencing of 44 intracranial aneurysm samples (including 21 unruptured, 22 ruptured and 1 undetermined) and 16 control samples of the intracranial cortical artery
RNA Sequencing Analysis of Intracranial Aneurysm Walls Reveals Involvement of Lysosomes and Immunoglobulins in Rupture.
Sex, Age, Subject
View SamplesColon cancer is a major cause of cancer deaths in Western countries and is associated with diets high in red meat. Heme, the iron-porphyrin pigment of red meat, induces cytotoxicity of gut contents which injures surface cells leading to compensatory hyperproliferation of crypt cells. This hyperproliferation results in epithelial hyperplasia which increases the risk of colon cancer. In humans, a high red-meat diet increases Bacteroides spp in feces. Therefore, we simultaneously investigated the effects of dietary heme on colonic microbiota and on the host mucosa of mice. Whole genome microarrays showed that heme injured the colonic surface epithelium and induced hyperproliferation by changing the surface to crypt signaling. Using 16S rRNA phylogenetic microarrays, we investigated whether bacteria play a role in this changed signaling. Heme increased Bacteroidetes and decreased Firmicutes in colonic contents. This shift was most likely caused by a selective susceptibility of Gram-positive bacteria to heme cytotoxic fecal water, which is not observed for Gram-negative bacteria, allowing expansion of the Gram-negative community. The increased amount of Gram-negative bacteria most probably increased LPS exposure to colonocytes, however, there is no appreciable immune response detected in the heme-fed mice. There was no functional change in the sensing of the bacteria by the mucosa, as changes in inflammation pathways and Toll- like receptor signaling were not detected. This unaltered host-microbe cross-talk indicates that the changes in microbiota did not play a causal role in the observed hyperproliferation and hyperplasia.
Dietary heme alters microbiota and mucosa of mouse colon without functional changes in host-microbe cross-talk.
Sex, Age, Specimen part
View SamplesPreviously, we showed that dietary heme injured the colonic surface epithelium and induced hyperproliferation by changing the surface to crypt signaling. In this study we investigated whether bacteria play a role in this changed signaling. Dietary heme increased the Bacteroidetes and decreased the Firmicutes in colonic content. This shift was caused by a selective susceptibility of Gram-positive bacteria to the heme cytotoxic fecal waters, which is not observed for Gram-negative bacteria allowing expansion of the Gram-negative community. The increased amount of Gram-negative bacteria increased LPS exposure to colonocytes, however, there is no appreciable immune response detected in the heme-fed mice. There were no signs of sensing of the bacteria by the mucosa, as changes in TLR signaling were not present. This lack of microbe-host cross talk indicated that the changes in microbiota do not play a causal role in the heme-induced hyperproliferation.
Dietary heme alters microbiota and mucosa of mouse colon without functional changes in host-microbe cross-talk.
Sex, Age, Specimen part, Treatment
View SamplesIn order to understand the molecular mechanism behind Vulvar Intraepithelial Neoplasia (VIN), we have analyzed the gene expression profile of VIN lesions in comparison to controls.
HPV related VIN: highly proliferative and diminished responsiveness to extracellular signals.
Sex
View SamplesOculopharyngeal muscular dystrophy (OPMD) is a late-onset progressive muscle disorder caused by a poly-alanine expansion mutation in PABPN1. The hallmark of OPMD is the accumulation of the mutant protein in insoluble nuclear inclusions. The molecular mechanisms associated with disease onset and progression are unknown. We performed a high-throughput cross-species transcriptome study of affected muscles from two OPMD animal models and from patients at pre-symptomatic and symptomatic stages. The most consistently and significantly OPMD-deregulated pathway across species is the ubiquitin-proteasome system (UPS). By analyzing expression profiles, we found that the majority of OPMD-deregulated genes are age-associated. Based on expression trends, disease onset can be separated from progression; the expression profiles of the proteasome-encoding genes are associated with onset but not with progression. In a muscle cell model, proteasome inhibition and the stimulation of immunoproteasome specifically affect the accumulation and aggregation of mutant PABPN1. We suggest that proteasome down-regulation during muscle aging triggers the accumulation of expPABPN1 that in turn enhances proteasome deregulation and leads to intranuclear inclusions (INI) formation.
Deregulation of the ubiquitin-proteasome system is the predominant molecular pathology in OPMD animal models and patients.
Sex, Age, Disease, Disease stage
View Samples